I have checked vacuum, I got 15 pounds when using a gauge connected to the hose leaving the distributed and going to the intake. I have installed new gaskets at the crossover pipe on both ends and triple checked the the turbo to crossover pipe.

Did you ever try having someone tow or push the car to get the engine turning over faster where it would pump more oil to the rings & build up the compression?? I know it sometimes helps when an engine sit a long time, I had a Plymouth Duster that wouldn't start & a friend said push it & it did start. Everything to gain & nothing to lose.

It's either spark or fuel since you have compression, so process of elimination. Assuming the ignition is fine since it was checked multiple times, I blame the stupid YH carb. I had nothing but troubles with that damn thing, never ran how I wanted it to. When it wasn't flooding out or generally running pig rich, it didn't work at all. Don't even try it without an electric fuel pump, all that gets you is a burned out starter after cranking it for 15 minutes because it boiled all the fuel out of the bowl. Same goes for hot shutdowns and subsequent attempts at restarting the next day- empty bowl=crank crank crank. If you don't have an electric pump under the tank, get one.

After that, here's what you do: have a friend crank the engine and shoot some starting fluid through the partially open carb throat, if it coughs and tries to run you have your answer. If not you still have ignition issues to sort through, easy peasy.

I tried the starting fluid and it coughed once or twice then just went back to cranking. Also I did a compression test with oil on my weaker side and all the numbers jumped over 210, and then I did it in the strong side and they're all over 215. Some on the cylinders go into the 280s. Since I had oil in the cylinders I tried the crank it over because I had higher compression, this is when I used the ether, it coughed, tried to start and went back to cranking

I would say that your tests using starter fluid are somewhat inconclusive, but may help to confirm that the ignition system is functioning. The Carter YH carburetor may still be the problem, in that it does not appear to be delivering a proper mix of fuel and air to the combustion chambers. These carburetors seem to be more faulty in design than most, and are difficult to correct. As mentioned earlier, a very experienced mechanic with a great deal of turbocharged Corvair expertise has never been satisfied or completely successful in getting the Corvair Carter YH carburetor to function properly. It is not an easy problem to resolve, short of substituting another carburetor to try to find a satisfactory solution. If I owned the turbocharged Corvair I believe I would really want to find an alternative to the Carter YH carburetor. Short of doing that I'm really not sure what your next step would be.
I would not have expected to find a harmonic balancer on your engine, unless somebody had replaced the engine with a 164 CI engine. The harmonic balancers were introduced into the Corvair lineup in 1964, when the engine displacement was increased.

Under compression you could have fouled the plugs with a film of oil. I also noticed you said you had the rotor pointing to number one plug, did you rotate the dist. counter clockwise a little then tighten it down or hold the dist and turn the pulley with a wrench until the timing mark is is near 24.. It won't run very good on TDC if at all, you need to advance it if you haven't.

As mentioned earlier, a very experienced mechanic with a great deal of turbocharged Corvair expertise has never been satisfied or completely successful in getting the Corvair Carter YH carburetor to function properly.

It's either spark or fuel since you have compression, so process of elimination. Assuming the ignition is fine since it was checked multiple times, I blame the stupid YH carb. I had nothing but troubles with that damn thing, never ran how I wanted it to. When it wasn't flooding out or generally running pig rich, it didn't work at all. Don't even try it without an electric fuel pump, all that gets you is a burned out starter after cranking it for 15 minutes because it boiled all the fuel out of the bowl. Same goes for hot shutdowns and subsequent attempts at restarting the next day- empty bowl=crank crank crank. If you don't have an electric pump under the tank, get one.

After that, here's what you do: have a friend crank the engine and shoot some starting fluid through the partially open carb throat, if it coughs and tries to run you have your answer. If not you still have ignition issues to sort through, easy peasy.

I don't believe he has ever expressed a great deal of love for the Carter YH carburetor!

I don't believe he has ever expressed a great deal of love for the Carter YH carburetor!

None whatsoever. When I saw an old picture of a Vette with three of them, I nearly puked.

I understand there have been a few that got a YH to do a reasonably good job, but not without a whole lot of futzing around. At the end of the day I just need something that works without all the fuss, and that's a Weber.

I always wondered why there was always a problem with the YH carbs, GM used them on the 53 to 55 Corvette's. I'm sure there more Corvette restoration shops than Corvairs. If I had a turbo with carb problems I would look for a Vette restorer for some help.

After reading all the advice it appears to me that his trouble lies within that yh.
Although Ray rebuilt it, doesn't mean the float was not damaged
in shipment! You said you have almost memorized Helt's yh book. Take the bowl cover off and make sure the float has not developed
a hole and thus taking on fuel, making the fuel leaking out the throat of the carb! Or as mentioned before, the float might have been knocked loose from the pivot pin.
Be sure to look at all the internal components and compare then with the pics in Bob's book.
The yh is harder to get right than most carburetors, but once you get it dialed in you will be fine.
Good luck

Having just gone through something similar with the YH on my car, I have two suggestions that are worth having a look at.

1. Check your fuel pressure. If you are running a mechanical pump, there is a good chance it is way too high. Remember in BH's book it said these carbs respond well to pressures around 3 psi? I ruined a 140 engine in my car once, measured the pressure and it was 9-1/2 Lbs with the mechanical fuel pump. First showed up as gas seepage through the gasket at the top of the carb bowl. The reason I didn't suspect the pump was I had that same issue with three different pumps. Learned that lesson too late, so now I am a firm believer in pressure regulators, especially adjustable ones. I just installed one on my car to go with the electric pump that supposedly won't pump over 4 psi. Then I played with it, adjusting pressure and driving around the block over and over. Pretty eye opening just how much those YH's respond to different pressures.

2. Check the adjustment of the choke. Mine now starts great, they do when the choke is working right. But if the choke is not right, it won't start at all without starting fluid.